Section 28. Using the Smart Sharpen Filter


#28. Using the Smart Sharpen Filter

The Unsharp Mask filter has been the ultimate tool many of us reach for to bring clarity and crispness to our images. With Photoshop CS2, the new Smart Sharpen filter gives the old standard a run for its money. This filter can produce some remarkable results, especially in comparison to what we're used to seeing from the Unsharp Mask filter. This is understandable though, considering that Smart Sharpen offers more controls to adjust how the sharpening is applied and where it occurs.

Fix Sharpening Color Shifts

Sometimes when you sharpen a brightly colored image, the colors will shift or become oversaturated. To overcome this problem, choose Edit > Fade sharpen filter immediately after applying the sharpen filter. Then select Luminosity from the Mode menu. This should eliminate the color from shifting.


Give the filter a try to get a sense of how it measures up to the classic Unsharp Mask filter. Open an image and view it at Actual Pixels (100%) to get an accurate view of the sharpening effect. Choose Filter > Sharpen > Smart Sharpen. Notice that the filter offers Basic and Advanced modes in the dialog. Even in the Basic mode it includes more options than the Unsharp Mask filter. Both tools offer Amount and Radius settings, but the Smart Sharpen filter includes a Remove menu to choose the type of blur to remove: Gaussian, Lens, or Motion (Figure 28a):

  • Leaving the Remove option on Gaussian Blur gives you results similar to the Unsharp Mask filter.

  • Lens Blur is a bit more refined, allowing you to increase your Amount value before noticeable halos appear. A halo effect occurs around the edges of an image when oversharpening an image. Keeping halos in check is the fine art of sharpening.

  • The Motion Blur option is ideal when your shot has a slight blur because the object or the camera moved slightly. The key is to find the best angle of the blur for the filter to work its magic.

Figure 28a. The Smart Sharpen filter includes a Basic and Advanced mode. It also lets you choose between three types of blur removal options.


Sharpening with the High Pass Filter

Here's a completely different sharpening technique that doesn't even use a sharpening filter. Duplicate the layer you want to sharpen (Layer > New > Layer via Copy). Then choose Filter > Other > High Pass, select a radius amount (somewhere between 3 and 7 is a good start), and click OK. Now change the layer's blending mode to Overlay, Soft Light, or Hard Light. You can then adjust the layer's opacity to control the amount of sharpening. Although some argue that this technique yields better results than applying a sharpening filter, it's still highly debatable as to which is really better. I suggest trying each and judge for yourself which one works best.


The More Accurate option runs the filter in two passes. This is similar to the technique many users employ of running a weak Unsharp Mask filter twice instead of running a strong one once. I suggest leaving this option on unless you're working with an image with a lot of grain or compression artifacts. This option actually runs the filter twice so it will take longer, but it's worth the wait.

Selecting the Advanced mode makes available the Shadow and Highlight tabs (Figure 28b). These tabs allow you to selectively control the amount of sharpening that occurs in the light and dark areas of your image, providing you with independent controls to reduce halos in just these areas.

Figure 28b. For even greater control on how the sharpening filter is applied, switch to the Advanced mode. Here you can separately adjust the shadow and highlight settings.





Adobe Creative Suite 2 How-Tos(c) 100 Essential Techniques
Adobe Creative Suite 2 How-Tos: 100 Essential Techniques
ISBN: 0321356748
EAN: 2147483647
Year: 2005
Pages: 143

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